/Engine/Source/Runtime/Engine/Public/HLSLTree/HLSLTreeCommon.h
Similar toFExpressionSwizzle, except swizzle parameters are extracted from a 'Mask' expression, which is expected to generate a 'bool4' component mask (which is then used to initialize aFSwizzleParameters) The 'Mask' input is required to be constant (otherwise an error is generated) This is used to support material StaticParameterMask expressions, in most casesFExpressionSwizzleis a better choice
class FExpressionComponentMask : public [UE::HLSLTree::FExpression](API\Runtime\Engine\HLSLTree\FExpression)
constFExpressi...
Input
constFExpressi...
Mask